PowerColor Radeon HD 6850 PCS+ Review - PAGE 3

The PCS+ models from PowerColor use an improved cooling solution that increase the overall cooling efficiency of the card, and reduces the noise level as well. On this model PowerColor used a large heatpipe-based heatsink with a 90mm fan that is attacked to a sleek black heatsink shroud. PowerColor states the improved cooling should increase the cooling performance by 15%, and lower the maximum dBA.

The heatsink is attacked to the shroud via four small screws. After the the screws are removed the heatsink can be separated from the cover, but the fan stays attached. The fan is 90mm and uses a PWM controller to adjust the rotation according to the internal GPU temperature. Since the fan is attached to the shroud there is ample distance between the fan and cooler, which improves the airflow and allows more of the array to be effected by it.

The heatsink used on this model has a large rectangular finned array that connects to the core and has three copper heatpipes that come out the side. The heatpipes increase the cooling efficiency of the heatsink, as does the large surface area of the array, reducing the operating temperature of the HD 6850's Barts GPU.

The base of the heatsink has a large surface area that makes direct contact with the GPU. There is a fair amount of thermal paste applied to the base, which ensures the heat is properly transferred away from the core where it can then migrate up to the array and eventually out of the card.

The PowerColor HD 6850 PCS+ uses the new Barts Pro graphics processing unit, built on a 40nm silicon fabrication process and has a total die size of 255mm². Even though the die size is 31% of Cypress core, the Barts GPU still manages to include 12 SIMDs (divided between two clusters) that each have 80 Stream Processors per cluster, giving the HD 6850 a total of 960 Stream Processors. Additionally, the Barts Pro GPU utilizes 32 Raster Operation Processors (ROPs), 48 texture units and with this being a PCS+ model the GPU clock frequency is increased from 775MHz to 820MHz. The included memory on the PowerColor HD 6850 PCS+ is manufactured by Hynix and there is a total of 1GB of GDDR5 memory that is rated at 1100MHz (4400MHz effective) and is processed through a 256-bit memory bus.

Overclocking:

Even with the increased frequencies I was hoping the PowerColor PCS+ had some additional overclocking headroom in it. This is because previous HD 6850 graphics cards that have made it to our labs were able to increase in clock speeds quite significantly, which is in direct contrast to its older sibling the HD 6870. After I started overclocking the memory and core clocks I could quickly tell the PowerColor PCS+ had plenty of additional room to play with, as it continuously passed stability test after test. At the end of the testing processes the PowerColor HD 6850 PCS+ was able to increase the core clock by 161MHz to 981MHz, which is an increase of near 20%. the memory also scaled very well, and was able to add an additional 104Mhz to the speed for a total rating of 1204MHz (4816MHz effective).

Comments

Hey thumbs up on your review. I like that you took the time to provide measurements and even breakdown the heatsink for us. We seem to have quite the collection of bench comparisons now too so that's really nice to see as well. I don't feel a need to check out other benches unless to do sli/xfire comparisons.

I don't know if maybe there's some kind of benches we can look at doing to compare GPU power for apps like video conversion or distributed computing but that'd probably have to start somewhere to review for all cards too.